Simulation of Process of Reproducing the Measuring Signal of a Magnetostrictive Displacement Transducer on Ultrasonic Torsion Waves for a Triangular Excitation Pulse

Author(s):  
Yu. N. Slesarev ◽  
A. A. Vorontsov
1968 ◽  
Vol 11 (1) ◽  
pp. 189-193 ◽  
Author(s):  
Lois Joan Sanders

A tongue pressure unit for measurement of lingual strength and patterns of tongue pressure is described. It consists of a force displacement transducer, a single channel, direct writing recording system, and a specially designed tongue pressure disk, head stabilizer, and pressure unit holder. Calibration with known weights indicated an essentially linear and consistent response. An evaluation of subject reliability in which 17 young adults were tested on two occasions revealed no significant difference in maximum pressure exerted during the two test trials. Suggestions for clinical and research use of the instrumentation are noted.


2021 ◽  
Vol 13 (13) ◽  
pp. 7174
Author(s):  
Massimo Rundo ◽  
Paolo Casoli ◽  
Antonio Lettini

In hydraulic components, nonlinearities are responsible for critical behaviors that make it difficult to realize a reliable mathematical model for numerical simulation. With particular reference to hydraulic spool valves, the viscous friction coefficient between the sliding and the fixed body is an unknown parameter that is normally set a posteriori in order to obtain a good agreement with the experimental data. In this paper, two different methodologies to characterize experimentally the viscous friction coefficient in a hydraulic component with spool are presented. The two approaches are significantly different and are both based on experimental tests; they were developed in two distinct laboratories in different periods of time and applied to the same flow compensator of a pump displacement control. One of the procedures was carried out at the Fluid Power Research Laboratory of the Politecnico di Torino, while the other approach was developed at the University of Parma. Both the proposed methods reached similar outcomes; moreover, neither method requires the installation of a spool displacement transducer that can significantly affect the results.


2019 ◽  
Vol 252 ◽  
pp. 02002
Author(s):  
Michał Jakubowicz ◽  
Mirosław Rucki ◽  
Zbigniew Siemiątkowski

The paper describes the test rig dedicated for air gauge dynamical characteristics assessment. The computerised system enables measurement of the amplitudes of back-pressure pk dependent on the input signal circular frequency ω. Dedicated software performs full control on the calibration procedure, which consists of setting a rotational speed and registration of measuring signal, and further data processing. Circular frequency ω was gradually changed with the appropriate step, in order to obtain a series of frequencies in the range from 0.1 to 20 Hz. The response of a measurement system was registered as a sinusoidal curve which after smoothening and interpolation procedures provided an amplitude-frequency graph with its main characteristics, such as time constant and the frequency f0.95 that generated dynamic error 5%. It was demonstrated that sine input dynamic calibration corresponds with real conditions of the in-process measurement with air gauges.


2016 ◽  
Vol 59 (8) ◽  
pp. 832-837 ◽  
Author(s):  
S. A. Matyunin ◽  
M. V. Stepanov ◽  
O. G. Babaev

2015 ◽  
Vol 22 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Zbigniew Korczewski

Abstract The article discusses the problem of diagnostic informativeness of exhaust gas temperature measurements in turbocharged marine internal combustion engines. Theoretical principles of the process of exhaust gas flow in turbocharger inlet channels are analysed in its dynamic and energetic aspects. Diagnostic parameters are defined which enable to formulate general evaluation of technical condition of the engine based on standard online measurements of the exhaust gas temperature. A proposal is made to extend the parametric methods of diagnosing workspaces in turbocharged marine engines by analysing time-histories of enthalpy changes of the exhaust gas flowing to the turbocompressor turbine. Such a time-history can be worked out based on dynamic measurements of the exhaust gas temperature, performed using a specially designed sheathed thermocouple. The first part of the article discusses possibilities to perform diagnostic inference about technical condition of a marine engine with pulse turbocharging system based on standard measurements of exhaust gas temperature in characteristic control cross-sections of its thermal and flow system. Selected metrological issues of online exhaust gas temperature measurements in those engines are discusses in detail, with special attention being focused on the observed disturbances and thermodynamic interpretation of the recorded measuring signal. Diagnostic informativeness of the exhaust gas temperature measurements performed in steady-state conditions of engine operation is analysed in the context of possible evaluations of technical condition of the engine workspaces, the injection system, and the fuel delivery process.


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